" It was in postwar Paris that Mandelbrot began this quest in earnest. Uncle Szolem urged him to attend the École Normale Supérieure, France’s most rarefied institution of higher learning, where Mandelbrot had earned entry at the age of twenty (one of only twenty Frenchmen to do so). But the aridly abstract style of mathematics practiced there was uncongenial to him. At the time, the École Normale—dite normale, prétendue supérieure, says the wag—was dominated in mathematics by a semisecret cabal called Bourbaki. (The name Bourbaki was jocularly taken from a hapless nineteenth-century French general who once tried to shoot himself in the head but missed.) Its leader was André Weil, one of the supreme mathematicians of the twentieth century (and the brother of Simone Weil). The aim of Bourbaki was to purify mathematics, to rebuild it on perfectly logical foundations untainted by physical or geometric intuition. Mandelbrot found the Bourbaki cult, and Weil in particular, “positively repellent.” The Bourbakistes seemed to cut off mathematics from natural science, to make it into a sort of logical theology. They regarded geometry, so integral to Mandelbrot’s Keplerian dream, as a dead branch of mathematics, fit for children at best. "
― Jim Holt , When Einstein Walked with Gödel: Excursions to the Edge of Thought